Unisoft Technologies Nagpur

This blog will demonstrate detailed steps to restore a database on New Host using RMAN. You can also use it to move a production database to new host as test database. Here, we are going to use the source database with the DB_NAME=ORCL and we are going to restore this ORCL database on the test database machine. 1. Preparing to restore the database on a new host: If you use the procedure in this section, then the DBID for the restored database equals the DBID for the original database. Do not register a test database created in this way in the same recovery catalog as the source database. Because the DBID of the two databases is the same, the metadata for the test database can interfere with RMAN's ability to restore and recover the source database.  Record the DBID for your source database. You can find the DBID by connecting to the database with RMAN as shown below: Take backups of all the datafiles, controlfiles, spfile and archivelog files on the source database ...

   REMAP_DATA Default: There is no default Purpose The REMAP_DATA parameter allows you to specify a remap function that takes as a source the original value of the designated column and returns a remapped value that will replace the original value in the dump file. A common use for this option is to mask data when moving from a production system to a test system. For example, a column of sensitive customer data such as credit card numbers could be replaced with numbers generated by a REMAP_DATA function. This would allow the data to retain its essential formatting and processing characteristics without exposing private data to unauthorized personnel. The same function can be applied to multiple columns being dumped. This is useful when you want to guarantee consistency in remapping both the child and parent column in a referential constraint. Syntax and Description REMAP_DATA=[ schema .] tablename . column_name :[ schema .] pkg . function The descri...

Understand Deferred Segment Creation Beginning with Oracle Database 11 g Release 2, when you create heap-organized tables in a locally managed tablespace, the database defers table segment creation until the first row is inserted. In addition, segment creation is deferred for any LOB columns of the table, any indexes created implicitly as part of table creation, and any indexes subsequently explicitly created on the table. Note: In Release 11.2.0.1, deferred segment creation is not supported for partitioned tables. This restriction is removed in release 11.2.0.2 and later. The advantages of this space allocation method are the following: It saves a significant amount of disk space in applications that create hundreds or thousands of tables upon installation, many of which might never be populated. It reduces application installation time. There is a small performance penalty when the first row is inserted, because the new segment must be created at that ...

Purpose of the Recovery Catalog A recovery catalog is a database schema used by RMAN to store metadata about one or more Oracle databases. Typically, you store the catalog in a dedicated database. A recovery catalog provides the following benefits: A recovery catalog creates redundancy for the RMAN repository stored in the control file of each target database . The recovery catalog serves as a secondary metadata repository. If the target control file and all backups are lost, then the RMAN metadata still exists in the recovery catalog. A recovery catalog centralizes metadata for all your target databases. Storing the metadata in a single place makes reporting and administration tasks easier to perform. A recovery catalog can store metadata history much longer than the control file. This capability is useful if you must do a recovery that goes further back in time than the history in the control file. The added complexity of managing a recovery catal...

About Virtual Private Catalogs By default, all of the users of an RMAN recovery catalog have full privileges to insert, update, and delete any metadata in the catalog. For example, if the administrators of two unrelated databases share the same recovery catalog, each administrator could, whether inadvertently or maliciously, destroy catalog data for the other's database. In many enterprises, this situation is tolerated because the same people manage many different databases and also manage the recovery catalog. But in other enterprises where clear separation of duty exists between administrators of various databases, as well as between the DBA and the administrator of the recovery catalog, you may desire to restrict each database administrator to modify only backup metadata belonging to those databases that they are responsible for, while still keeping the benefits of a single, centrally-managed, RMAN recovery catalog. This goal can be achieved by implementing v...

Oracle 11g New Feature - Duplicating a Oracle Database Using 11g RMAN Backup Location Option but Without Connection to Target or  Recovery Catalog We have Target Database name as ORCL And we are creating a duplicate database using RMAN Auxiliary Instance with name as AUXDB by using the backup location but without making connection to target database and recovery catalog database while the duplication process is running. Note :- This practical need same directory structures and it is performed on same server. Just the database name is different so we are converting the path with respect to dbname only.  Image Source - docs.oracle.com Your Target Database can be in any log mode. Take RMAN Backup based on your Database Log Mode. A) Archivelog Mode - Take a Whole Hot Backup C:\set ORACLE_SID=orcl C:\rman target / RMAN> backup database plus archivelog; B) Noarchivelog Mode - Take a Whole Cold Backup C:\set ORACLE_SID=orcl C:\rman targe...

Figures shown in these notes are from Oracle® Database Concepts 11 g Release 2 Objectives These notes introduce the Oracle server architecture.   The architecture includes physical components, memory components, processes, and logical structures. Primary Architecture Components The figure shown above details the Oracle architecture. Oracle server :   An Oracle server includes an Oracle Instance and an Oracle database .   ·         An Oracle database includes several different types of files:   datafiles, control files, redo log files and archive redo log files.   The Oracle server also accesses parameter files and password files.   ·         This set of files has several purposes.   o    One is to enable system users to process SQL statements.   o    Another is to improve system performance.   o    Still a...